Electrically driven device

Patent metadata

Field	Value
Publication number	US-10502291-B2
Application number	US-201715715109-A
Country	US
Kind code	B2
Filing date	Sep 25, 2017
Priority date	Sep 28, 2016
Publication date	Dec 10, 2019
Grant date	Dec 10, 2019

Abstract

An electrically driven device includes a housing, an electric motor with a drive shaft having a first rotary axis and a drive pin connected to the drive shaft eccentrically with respect to the rotary axis, and a driven shaft having a second rotary axis and mounted in the housing for performing a pivoting about the second rotary axis. The driven shaft is coupled to the drive shaft by a gear mechanism including a scotch yoke mechanism converting a rotary motion of the drive shaft into a reciprocating motion of the driven shaft. The scotch yoke mechanism includes a cross slider having a sliding support extending perpendicular to the first rotary axis and receiving the drive pin either directly or through a sliding block with a bearing receiving the drive pin. The cross slider is guided in the housing by at least two pivotable links. The driven shaft is coupled to the cross slider by an arm, converting a rotary motion of the drive shaft into a reciprocating of the driven shaft.

First claim

What is claimed is:

1. An electrically driven device comprising
a housing ( 4 ),
an electric motor ( 1 ) mounted in the housing ( 4 ) and comprising a drive shaft ( 2 ) having a first rotary axis (I),
a driven shaft ( 12 ) having a second axis (II) and mounted in the housing ( 4 ) for performing a movement relative to the housing ( 4 ),
wherein the driven shaft ( 12 ) is indirectly coupled to the drive shaft ( 2 ) by means of a gear mechanism comprising a scotch yoke mechanism ( 5 , 7 ) converting a rotary motion of the drive shaft ( 2 ) into an oscillating motion of the driven shaft ( 12 ),
wherein
a drive pin ( 3 ) is connected to the drive shaft ( 2 ) eccentrically with respect to the rotary axis (I), the scotch yoke mechanism comprises a cross slider ( 7 ) having a sliding support ( 6 ) which extends perpendicular to the first rotary axis (I) and which receives the drive pin ( 3 ) either directly or by means of a sliding block ( 5 ) having a bearing receiving the drive pin ( 3 ), wherein the cross slider ( 7 ) is guided in the housing ( 4 ) by means of at least two pivotable links ( 8 , 9 ), and
the driven shaft ( 12 ) is coupled to the cross slider ( 7 ) by means of a pivotable arm ( 13 ), thereby converting a rotary motion of the drive shaft ( 2 ) into an oscillating motion of the driven shaft ( 12 ),
wherein each of the at least two pivotable links ( 8 , 9 ) is pivotably hinged to a bearing point ( 10 ) of the housing ( 4 ) and pivotably hinged to a bearing point ( 11 ) of the cross slider ( 7 ) such that the cross slider ( 7 ) is guided to be moveable on a curved track with respect to the housing ( 4 ),
wherein for each of the pivotable links ( 8 , 9 ) a distance (L 1 ) between the bearing point ( 10 ) of the housing ( 4 ) and the bearing point ( 11 ) of the cross slider ( 7 ) is identical,
wherein the distance (L 1 ) of the pivotable links ( 8 , 9 ) between the bearing point ( 10 ) of the housing ( 4 ) and the bearing point ( 11 ) of the cross slider ( 7 ) differs from a distance (L 2 ) of the pivotable arm ( 13 ) between the bearing point ( 15 ) of the cross slider ( 7 ) and the second axis (II) of the driven shaft ( 12 ), and
wherein the driven shaft ( 12 ) is pivotably mounted in the housing ( 4 ) by means of a rocker frame ( 14 ) which is pivotable with respect to the housing ( 4 ) about a pivoting axis (IV) which is perpendicular to the first rotary axis (I) and perpendicular to an extension (III) of the sliding support ( 6 ).

2. The electrically driven device according to claim 1 , wherein the pivotable arm ( 13 ) is pivotably hinged to a bearing point ( 15 ) of the cross slider ( 7 ) and rotationally constrained to an anchorage point of the driven shaft ( 12 ).

3. The electrically driven device according to claim 2 , wherein the distance (L 1 ) of the pivotable links ( 8 , 9 ) between the bearing point ( 10 ) of the housing ( 4 ) and the bearing point ( 11 ) of the cross slider ( 7 ) is identical to the distance (L 2 ) of the pivotable arm ( 13 ) between the bearing point ( 15 ) of the cross slider ( 7 ) and the second axis (II) of the driven shaft ( 12 ).

4. The electrically driven device according to claim 1 , wherein the distance (L 1 ) of the pivotable links ( 8 , 9 ) between the bearing point ( 10 ) of the housing ( 4 ) and the bearing point ( 11 ) of the cross slider ( 7 ) is identical to the distance (L 2 ) of the pivotable arm ( 13 ) between the bearing point ( 15 ) of the cross slider ( 7 ) and the second axis (II) of the driven shaft ( 12 ).

5. The electrically driven device according to claim 1 , wherein an elastically deformable element ( 17 ) is provided between the housing ( 4 ) and the rocker frame ( 14 ) biasing the rocker frame ( 14 ) into a rest position with respect to the housing ( 4 ).

6. The electrically driven device according to claim 5 , wherein the switch or sensor is arranged in the housing ( 4 ) such that the switch or sensor detects movement of the rocker frame ( 14 ) with respect to the housing ( 4 ) exceeding a threshold movement.

7. The electrically driven device according to claim 5 , wherein movement of the cross slider ( 7 ) generates an intermittent force (F X ) in a direction perpendicular to the axial movement of the cross slider ( 7 ) which intermittent force (F X ) is transmitted to the rocker frame ( 14 ) via the pivotable arm ( 13 ) and the driven shaft ( 12 ), with the intermittent force (F X ) biasing the rocker frame ( 14 ) away from the rest position.

8. The electrically driven device according to claim 7 , wherein the intermittent force (F X ) generated by the motion of the cross slider ( 7 ) exceeds the biasing force (F V ) of the elastically deformable element ( 17 ).

9. The electrically driven device according to claim 8 , wherein if the rocker frame ( 14 ) is in its rest position with respect to the housing ( 4 ) with the elastically deformable element ( 17 ) being unstressed, a user force is exerted on the driven shaft ( 12 ) is directed opposite to the intermittent force (F X ) generated by the motion of the cross slider ( 7 ).

10. The electrically driven device according to claim 1 , wherein a switch or sensor is provided and arranged in the housing ( 4 ) such that the switch or sensor detects movement of the rocker frame ( 14 ) with respect to the housing ( 4 ).

11. The electrically driven device according to claim 1 , wherein a first transmission stage of the gear mechanism converts a continuous rotary motion of the drive shaft ( 2 ) into a sinusoidal reciprocating displacement of the cross slider ( 7 ).

12. The electrically driven device according to claim 1 , wherein a bar ( 18 ) is provided constrained to the housing ( 4 ) and located at the end of the driven shaft ( 12 ) facing towards the motor ( 1 ).

Assignees

• Braun Gmbh

Inventors

• FRITSCH Thomas (NMN)
• KRAMP Andreas (NMN)
• SCHAEFER Norbert (NMN)

Classifications

• A61C17/34

  driven by electric motor · CPC title

• A61C17/221

  Control arrangements therefor · CPC title

• A61C17/3481

  Vibrating brush body, e.g. by using eccentric weights · CPC title

• H02K7/075

  using crankshafts or eccentrics · CPC title

• F16H21/40 Primary

  for interconverting rotary motion and oscillating motion · CPC title